Suturing by surgeons is currently generally accomplished by manual suturing of tissues, whereby the surgeon uses a fine pair of pliers to grab and hold a suture needle, pierce the tissue with the needle, let go of the needle, and regrab the needle to pull the needle and accompanying suture thread through the tissues to be sutured. Such needles may be curved or "C"-shaped, with the suture thread attached to the back end of the needle.
Automated suturing devices, including devices described as suitable for microsurgery, are known. For example, U.S. Pat. No. 4,557,265 to Andersson describes a suturing instrument for joining two edges of biological tissue, such as blood vessels, using an arcuate suture needle which is driven and rotated by friction rollers via a cylindrical fly-wheel and plunger rod arrangement with a pneumatic or other drive source, so that the suture thread forms a continuous suture looped through the two tissue edges. U.S. Pat. No. 4,899,746 to Brunk describes a suturing apparatus in which an electric motor drives a curved needle around in a circular path of travel by means of a gear arrangement connecting to a plurality of drive rollers in supporting and driving arrangement with the needle. U.S. Pat. No. 5,308,353 to Beurrier describes a surgical suturing device in which an arcuate needle having outward projecting angled barbs positively engages and is rotated by a continuous loop drive belt.
However, such known automated suturing devices have not found wide use due to the inherent deficiencies of their design and operation, including needle slippage, inefficient transfer of drive motion to the advancement of the needle, inefficient and impractical drive mechanisms, and generally poor performance of the devices, particularly for microsurgical applications where a very small size for the device is required. Accordingly, there is a need for an improved suturing device which overcomes these deficiencies.